It is known that micromechanical springs for suspending seismic masses in rotation rate sensors in part cause deflections in the readout direction in the drive mode simply because of relatively slight manufacturing inaccuracies, which in the absence of a rotation rate lead, in particular, to undesired flank angles of the respective structures. As a result of this, interference signals are generated that can undesirably be evaluated as rotation rate signal components, and thus corrupt the rotation rate signal and/or cause a measuring error with reference to the rotation rate signal.
Such undesired flank angles or tiltings of springs are process induced and can be avoided only to some degree. The above-described interference signals which are produced not owing to an acquired rotation rate but owing to defective deflections in the readout direction as a function of the deflection of the seismic mass and of the springs thereof in the drive direction, are also denoted as quadrature or quadrature signals.
Printed publication WO 03/010492 A1, which is incorporated by reference, proposes a method for suppressing quadrature signals in a rotation rate sensor that comprises two trimming electrode arrangements which are assigned to a seismic mass, in the case of which method the quadrature of the rotation rate sensor is suppressed by means of the voltage applied to the trimming electrodes. However, this quadrature suppression can have an undesirable influence on the resonant frequency of the readout mode of the rotation rate sensor, as a result of which the difference frequency between the resonant frequencies with regard to the drive mode and the readout mode of the rotation rate sensor is also changed. This is all the more disadvantageous because the voltage applied to the trimming electrodes is squared in the shift of the resonant frequency of the readout mode.
It is usual for the quadrature of rotation rate sensors of a wafer to exhibit relatively strong dispersion because of process fluctuations, and/or to differ relatively strongly from rotation rate sensor to rotation rate sensor of a wafer.